1、BSI Standards PublicationBS ISO 3548-1:2014Plain bearings Thin-walledhalf bearings with or withoutflangePart 1: Tolerances, design features andmethods of testBS ISO 3548-1:2014 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 3548-1:2014. Itsupersedes BS ISO 354
2、8:1999 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee MCE/12, Plain bearings.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a
3、contract. Users are responsible for its correctapplication. The British Standards Institution 2014. Published by BSI StandardsLimited 2014ISBN 978 0 580 76003 7ICS 21.100.10Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the a
4、uthority of theStandards Policy and Strategy Committee on 30 June 2014.Amendments issued since publicationDate Text affectedBS ISO 3548-1:2014 ISO 2014Plain bearings Thin-walled half bearings with or without flange Part 1: Tolerances, design features and methods of testPaliers lisses Demi-coussinets
5、 minces ou sans collerette Partie 1: Tolrances, caractristiques de conception et mthodes dessaiINTERNATIONAL STANDARDISO3548-1First edition2014-06-15Reference numberISO 3548-1:2014(E)BS ISO 3548-1:2014ISO 3548-1:2014(E)ii ISO 2014 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2014All rights re
6、served. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either
7、ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 3548-1:2014ISO 3548-1:2014(E) ISO 2014 All rights reserved
8、 iiiContents PageForeword iv1 Scope . 12 Normative references 13 Symbols 14 Dimensions and tolerances . 34.1 Housing diameter, half bearing outside diameter and crush height. 34.2 Half bearing wall thickness and bearing bore . 44.3 Width of half bearing, distance between flanges, outside diameter of
9、 flange and flange thickness 54.4 Free spread . 65 Design features. 75.1 Locating lip and recess . 75.2 Reliefs and chamfers 95.3 Transition between radial part and flange 105.4 Assembled flange scalloped toes 125.5 Oil grooves and holes 126 Test data for determining the peripheral length .156.1 Cal
10、culation of test force F 156.2 Checking method A 166.3 Checking method B . 177 Test data for determining axial width, B2, of flange bearings 177.1 Go between two parallel plates 177.2 Axial width B2checked under force 188 Function and characteristics of assembled flange bearings 188.1 Characteristic
11、s 198.2 Classification 208.3 Checklist of items for ensuring the function of assembled flange bearings 20Annex A (normative) Example of calculation .21Bibliography .22BS ISO 3548-1:2014ISO 3548-1:2014(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of nat
12、ional standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. Interna
13、tional organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.The procedures used to develop this document and those intend
14、ed for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.i
15、so.org/directives). Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document wi
16、ll be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents). Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expres
17、sions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary informationThe committee responsible for this document is ISO/TC 123, Plain Bearings, Subcommittee SC 3 D
18、imen-sions, tolerances and constructions details.,This first edition of ISO 3548-1 cancels and replaces the second edition of ISO 3548:1999, which has been technically revised.ISO 3548 consists of the following parts, under the general title Plain bearings Thin walled half bearings with or without f
19、lange: Part 1: Tolerances, design features and methods of test Part 2: Measurement of wall thickness and flange thickness Part 3: Measurement of peripheral lengthiv ISO 2014 All rights reservedBS ISO 3548-1:2014INTERNATIONAL STANDARD ISO 3548-1:2014(E)Plain bearings Thin-walled half bearings with or
20、 without flange Part 1: Tolerances, design features and methods of test1 ScopeThis part of ISO 3548 specifies tolerances, design features, and test methods for thin-walled half bearings with integral flange up to an outside diameter of Do= 250 mm and without flange up to an outside diameter of Do= 5
21、00 mm. Due to the variety of design, it is, however, not possible to standardize the dimensions of the half bearings.Half bearings according to this part of ISO 3548 are predominantly used in reciprocating machinery and consist of a steel backing and one or more bearing metal layers on the inside.In
22、 reciprocating machinery, flanged half bearings can be used in connection with half bearings without flange.Alternatively, to serve as a flanged half bearing, it is possible to use a half bearing without flange together with two separate half thrust washers according to ISO 6526; or a half bearing w
23、ith assembled flanges.NOTE All dimensions and tolerances are given in millimetres.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undat
24、ed references, the latest edition of the referenced document (including any amendments) applies.ISO 4288, Geometrical Product Specifications (GPS) Surface texture: Profile method Rules and procedures for the assessment of surface textureISO 6524, Plain bearings Thin-walled half bearings Checking of
25、peripheral lengthISO 6526, Plain bearings Pressed bimetallic half thrust washers Features and tolerances3 SymbolsSee Figures 1 and 2 and Table 1. ISO 2014 All rights reserved 1BS ISO 3548-1:2014ISO 3548-1:2014(E)Key1 joint face2 sliding surface3 bearing metal4 bearing back5 steel backFigure 1 Half b
26、earing without flange (with positive free spread)Figure 2 Flange half bearing (integral or assembled, excluding free spread)2 ISO 2014 All rights reservedBS ISO 3548-1:2014ISO 3548-1:2014(E)Table 1 Symbols and unitsSymbol Term Unita1Measuring point perpendicular to plane of joint face mmAcalReduced
27、area of cross section (calculated value) of half bearing mm2bHHousing width mmB1Half bearing width (without flange) mmB2Flange half bearing width mmB3Distance between flanges mmC1Outside chamfer mmC2Inside chamfer mmdchDiameter of the checking block bore mmdHHousing diameter mmDflOutside diameter of
28、 flange mmDiNominal Inside diameter of the half bearing (bearing bore) mmDoNominal Outside diameter of the half bearing mmDo,EOutside diameter of the half bearing in the free state (with free spread)mmeBAmount of eccentricity mmF Test force NFaxAxial test force for assembled flange bearings Nh Crush
29、 height, h = h1+ h2(in checking method B) mmp Amount of free spread mmsflFlange thickness mms1Thickness of the steel backing mms2Bearing metal thickness mms3Half bearing wall thickness mms4Wall thickness at base of groove mmu Amount of wall thickness reduction for eccentric bearing mm4 Dimensions an
30、d tolerances4.1 Housing diameter, half bearing outside diameter and crush heightThe housing diameter should be manufactured to ISO H6 limits. Thereby the half bearing outside diameter shall be selected with such an oversize that an adequate interference fit is ensured in the housing diameter.In the
31、case of housings made from materials having a high coefficient of expansion or where other factors such as housing dimensional stability are involved, the housing size may depart from tolerance class H6 but shall always be produced in accordance with a grade 6 tolerance.The half bearing in a free st
32、ate is flexible so that its outside diameter cannot be measured directly. Instead of this, its peripheral length is determined by means of special checking fixtures. The peripheral length results from the periphery of the checking block bore and the crush height taking into account the reduction und
33、er a given checking load per joint face (see Clause 6). For the calculation of the effective interference fit of the half bearings in the housing, see Reference 5. ISO 2014 All rights reserved 3BS ISO 3548-1:2014ISO 3548-1:2014(E)The tolerances given in Table 2 for the crush height apply to half bea
34、rings with machined joint faces. Different materials and housing design require different interference fits, therefore only tolerances are given in Table 2.4.2 Half bearing wall thickness and bearing boreNominal dimensions to be preferred for the wall thickness of the bearing are given in Table 2 (t
35、he particulars of the wall thickness for each application cannot be specified in general). Therefore, only tolerances can be given for the wall thickness. These tolerances and the surface roughnesses of the bearing back and the sliding surface of half bearings with or without electroplated antifrict
36、ion layers are given in Table 2.The tolerance for the half bearing wall thickness depends on the fact whether the bearing bore is subject to a final machining operation (i.e. “as machined”) or whether the bearing bore is electroplated without further machining (i.e. “as-plated”).Slight surface defor
37、mations are acceptable on the outside diameter of the bearing provided that they are not numerous. However, the measurement of the wall thickness shall not be carried out in these areas.The bearing bore in the fitted state results from the housing bore which is elastically enlarged by the press fit,
38、 reduced by twice the value of the half bearing wall thickness.5NOTE In certain applications it might be necessary to use plain or flange half bearings with eccentric bores, i.e. the wall thickness of the half bearing decreases uniformly from the crown to the joint faces (see Figures 3 and 4).The ec
39、centricity eBis characterized in a radial plane by the distance between the centre x1of the bearing outside surface and the centre x2of the bearing bore. eBis not dimensioned specifically. The eccentricity is controlled by the specified reduction u which is measured at a vertical distance a1from the
40、 plane of the joint face. (For guidance of draughtsmen, a1is generally specified so that the angle 2is approximately 25 from the joint face). It is subject to agreement between the user and manufacturer.Figure 3 Eccentric bearing bore of half bearing4 ISO 2014 All rights reservedBS ISO 3548-1:2014IS
41、O 3548-1:2014(E)Key1 crown2 joint faceFigure 4 Example of the wall thickness at different anglesThe tolerance limit for the behaviour of wall thickness can be calculated using Formulae 1 and 2:, ussBL2_ 1 sin 1 sin= 3,actBL(1)ssu,UL3,actUL=1 sin 1 sin 2(2)whereBLuis the bottom limit of u;ULuis the u
42、pper limit of u;s3, actis the actual value of s3;s, BLis the bottom value of s;s, ULis the upper value of s.For an example of calculations, see Annex A.4.3 Width of half bearing, distance between flanges, outside diameter of flange and flange thicknessThe nominal dimension for the half bearing width
43、 and the distance between flanges depends upon the type of application, the common ratio being B1(B2)/Di 0,5. The tolerances for the half bearing width are given in Table 2. The flange outside diameter should be smaller than the diameter of the shoulder of the shaft and smaller than the diameter of
44、the housing block.In most cases the flange thickness is fixed in conformity with the half bearing wall thickness and, in general, a tolerance is fixed only for the flange thickness of the pressure loaded side in order to ensure that these flanges of the upper and lower half bearing have approximatel
45、y the same thickness. In this case, the position of these flanges with respect to the locating lips is fixed.If the upper and lower half bearings are of the same design, then generally the two flanges of one half bearing shall have the same thickness within the tolerance range fixed in Table 2. In t
46、hat case, the flange thicknesses result from the bearing width and the distance between flanges. Nevertheless, another tolerance can be accepted after agreement between the user and the manufacturer (see Clause 7). ISO 2014 All rights reserved 5BS ISO 3548-1:2014ISO 3548-1:2014(E)4.4 Free spreadFree
47、 spread is influenced by factors such as the lining material, its thickness and its physical properties, by the bearing backing material and its properties, and by the operating temperature of the assembly. Since these features are not specified in this part of ISO 3548, it is not possible to specif
48、y free spread. Free spread shall in all circumstances be positive. After operation in the combustion engine at normal conditions, a sufficient amount of free spread remains in the bearing to enable it to be refitted. The actual amount of free spread shall be the subject of agreement between the manu
49、facturer and user.Half bearings for reciprocating machinery normally have a free spread of 0,2 mm up to 3 mm. For very large, thin-walled half bearings, the free spread may be greater but it shall not be such that the half bearing cannot be fitted into the housing.Table 2 Dimensions, tolerances and limit deviations for half bearings with and without flangeTolerance or limit deviation foraSurface rough-nessbcmHousing diameterWall thick-nessWall thicknessFlange thick-nessdeHalf bearing wid
copyright@ 2008-2019 麦多课文库（www.mydoc123.com）网站版权所有
备案/许可证编号：苏ICP备17064731号-1